term = {
    '注释':'行首有一特殊标志符号运行时告知编程忽略此行',
    '关键字':'编程语言中具有特殊意义的词',
    '数据类型':'将数据划分为不同的类别，数据所属的类别，即为数据类型',
    '对象':'Python中具有3个属性的数据值——唯一标识，数据类型和值',
    '字符':'例如：a,b,c,,1,2,3等单个符号'
}
for k,v in term.items():
    print(k+"："+v)
rivers = {
    'nile':'egypt',
    'yellow river':'china',
    'yangtze river':'china'
}
for k,y in rivers.items():
    print("The "+k.title()+" runs through "+y.title())
for river in rivers.keys():
    print(river.title())
for country in set(rivers.values()):
    print(country.title())

favorite_languages = {
    'jen': 'python',
    'sarah': 'c',
    'edward': 'ruby',
    'phil': 'python',
    '张三':'c',
    '李四':'java'
}
persons = ['王五','李四']
for f in favorite_languages:
    if f in persons:
        print("非常感谢"+f+"来参加本次调查。")
    else:
        print(f+"，您还未参加调查，请及时参加。")
